This invention relates to sweepers of either the manual or self-propelled type and more particularly to a unique roller-type dust seal positionable adjacent the inlet of a sweeper dust bin.
Industrial sweepers, whether of the push or the self-propelled type, are well known and are employed for cleaning shop areas, sidewalks and the like. These sweepers generally include some form of brush housing within which is mounted a rotatable, cylindrical-type brush. A dust receiving bin which is open at one end is mounted in a generally horizontal position, spaced slightly upward from the surface to be cleaned and adjacent the brush. Debris contacted by the rotating brush is swept upwardly and deposited into the bin.
Some form of seal arrangement must be positioned at the pickup junction or the area adjacent the lower, transversely extending lip of the bin. A depending flap secured to the lower lip and extending downwardly to the surface to be swept has been employed to prevent debris from being propelled through the open area between the brush and the bin. When fairly large debris is encountered, the flap has a tendency either to raise along a substantially large portion of its length, or merely push the debris forwardly thereby resulting in an ineffective seal.
In an attempt to alleviate these sealing problems, various forms of roller-type seals have been proposed. For example, U.S. Pat. No. 2,689,367 to Parker, entitled SWEEPER and issued on Sept. 21, 1954, discloses a push sweeper arrangement incorporating a fixedly positioned axle extending transversely along the lower lip of a dust receiving bin. Positioned on the axle are a plurality of generally hollow, cylindrical roller segments formed of a rubber material. Due to the manner of attachment of the axle to the dust receiver, a fairly elaborate mechanism must be incorporated to provide for vertical adjustment of the open end of the bin to insure proper contact of the rollers with the surface being cleaned.
Another example of a roller-type dust seal may be found in U.S. Pat. No. 3,201,819 to Wilgus, entitled SWEEPER and issued on Oct. 24, 1965. This patent discloses a self-propelled sweeper incorporating a vertically movable sub-frame and a pair of spaced, generally parallel axles extending between side plates of the sub-frame. The ends of the axles are received within vertically extending slots in the side plates and a plurality of generally hollow rollers are positioned on each axle. This arrangement, while permitting vertical movement of the rollers and the axle with respect to the side frame, is a fairly complex and bulky structure not readily adaptable to the wide variety of sweepers which are presently available.
A need exists, therefore, for a relatively simple roller-type dust seal which is readily adaptable to the wide variety of presently available sweepers and which automatically adjusts to depressions in the surface being swept and readily raises to permit passage of large articles encountered during the sweeping process.